Field of the Invention
The present invention relates to a medical manipulator used while inserted into a body cavity, and a control method of controlling the medical manipulator.
Description of Related Art
Recently, in order for a doctor to easily perform surgery, research on a medical treatment using a manipulator that can be deformed in various forms such as a bending motion, a moving motion, or the like, has been carried out. In order to reduce a stress on a patient during surgery, performing surgery after the introduction of an insertion section from an opening formed in a body wall into a body cavity or the like has been considered.
For example, an endoscopic surgical instrument disclosed in PCT International Publication No. WO 2007/097034 is constituted by a trocar for endoscopic surgery, a processor, a display, and a treatment tool.
The trocar is a guide member having a hollow shaft passing through a body wall. A connecting member is attached to a distal end section of the hollow shaft by a connecting pin. The connecting member has a telescopic structure including a main body section near the connecting pin and a slider slidably inserted into the main body section. As a protrusion amount of the slider with respect to the main body section is controlled, a length of the connecting member can be varied. An imaging device (an imaging section) is turnably attached to a distal end section of the slider by the connecting pin. An output signal of the imaging device is input into the processor.
The connecting member is turned about the connecting pin by a motor, an expansion/contraction amount of the connecting member is controlled, and the imaging device is turned about the connecting pin. The processor includes a signal processor configured to process a signal from the imaging device, a control circuit configured to calculate a protrusion amount or the like of the connecting member, and a driving circuit configured to drive the motor. The signal processor has an inclination detector configured to calculate an inclination amount of the hollow shaft when the hollow shaft is inclined about a substantial center of a portion thereof passing through the body wall as a support point. The control circuit calculates a turning amount and the expansion/contraction amount of the connecting member such that the imaging device is disposed at substantially the same position before and after the hollow shaft is inclined, using the inclination amount calculated by the inclination detector. The driving circuit swivels and expands/contracts the connecting member, and swivels the imaging device.
In the treatment tool, a rigid treatment tool insertion section extends from the manipulation unit manipulated by an operator such as a doctor or the like and is exchangeably inserted into the trocar. A treatment section such as a pair of gripping forceps is provided at a distal end of the treatment tool insertion section. A handle configured to open and close the pair of gripping forceps and a manipulation device such as a button or the like configured to manipulate the above-mentioned motor are provided at the manipulation unit.
Effects of the endoscopic surgical instrument having the above-mentioned configuration are as follows. The operator manipulates the manipulation device to dispose the hollow shaft, the connecting member, and the imaging device on the same axis. These are inserted into the body cavity through the trocar. When the operator manipulates the manipulation unit and the hollow shaft is inclined using the body wall as a support point, the above-mentioned control circuit and driving circuit swivel the imaging device. For this reason, the imaging device can maintain a state in which the observation images are substantially matched on a display screen of the display while being affected little due to inclination of the hollow shaft.